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Technical Service Center — Water Conveyance Group

Tunnels


The Bureau of Reclamation designs tunnels to provide various functions. These functions can be:

Reclamation engineers maintain a database of water conveyance tunnels. The database also contains information on some other tunnels.

Tunnel construction begins by excavating the ground. Tunnelers excavate tunnels using various methods including:

Material that is being excavated must be removed from the tunnel. TBM's use conveyor belts to transport the waste material away from the heading to a second conveyor belt or muck train. Drill and blast operations many times use load-haul-dump (LHD) machines to transport the waste material from the heading to the waste pile outside the tunnel.

The excavated hole must remain open as excavation at the heading progresses. If the ground cannot support itself until final support is installed then miners must install initial support. The tunnel can be initially supported by various methods. The most common are:

If the excavated opening cannot remain open for the life of the tunnel than the opening is permanently held open using final support. Concrete linings are usually used for final support. Tunnelers do this by using concrete forms on the inside face and pumping concrete into the space between the concrete forms and rock

Sometimes these are the same supports, for example:


E-mail one of us with your questions or comments!

Kevin Atwater for information on tunnels or these tunnel Web pages.
Tim Brown for information on water conveyance systems.